Harley-Davidson XR-750

The Harley-Davidson XR-750 is a racing motorcycle made by Harley-Davidson since 1970, built mainly for dirt track racing, with an XRTT variant for road racing. It was designed in response to the American Motorcyclist Association's 1969 rule change that set a single 750 cc limit for Grand National dirt track racing, which let British and Japanese overhead-valve machines overtake the flathead Harley-Davidson KR that had dominated the class. Racing manager Dick O'Brien and his team assembled the new bike from existing designs under tight time and money limits. The XR-750 went on to win more races than any other machine in AMA racing history. It is associated with the racers Mark Brelsford, Cal Rayborn and Jay Springsteen and was the favourite of stunt performer Evel Knievel, one of whose bikes is in the Smithsonian's National Museum of American History.